Showing papers in "Ecological Modelling in 2002"

TL;DR: A form of k -fold cross validation for evaluating prediction success is proposed for presence/available RSF models, which involves calculating the correlation between RSF ranks and area-adjusted frequencies for a withheld sub-sample of data.

TL;DR: A series of papers prepared within the framework of an international workshop entitled: Advances in GLMs /GAMs modeling: from species distribution to environmental management, held in Riederalp, Switzerland, 6 � /11 August 2001 are introduced.

TL;DR: In this article, an ecological model concerning the ecological theory to be used or tested, a data model concerning collection and measurement of the data, and a statistical model concerning statistical theory and methods used.

TL;DR: In this article, a method for detecting and quantifying spatial patterns over a wide range of scales is proposed by eigenvalue decomposition of a truncated matrix of geographic distances among the sampling sites.

TL;DR: The authors explored sample size needs for accurate modeling for three predictive modeling methods via re-sampling of data for well-sampled species, and developed curves of model improvement with increasing sample size.

TL;DR: By extending randomization approaches to ANNs, the “black box” mechanics of ANNs can be greatly illuminated and by coupling this new explanatory power of neural networks with its strong predictive abilities, ANNs promise to be a valuable quantitative tool to evaluate, understand, and predict ecological phenomena.

TL;DR: The GAM framework based on backfitting with linear smoothers presents some diculties when it comes to model selection and the availability of user friendly GAM software in Splus.

TL;DR: In this article, a cellular automata model called dinamica is used to simulate spatial patterns of land-use and land-cover changes produced by the Amazonian colonists in clearing the forest, cultivating the land and eventually abandoning it for vegetation succession.

TL;DR: In this paper, the authors compared generalized additive models (GAM) and ecological niche factor analysis (ENFA) models fitted with identical presence data and computer generated "pseudo" absences.

TL;DR: In this article, the authors compared four sampling strategies, namely, "random", "regular", "proportional-stratified" and "equal-stated", to investigate how they affect prediction accuracy and how sensitive they are to sample size.

TL;DR: This paper presents a spatially explicit hierarchical modeling approach to studying the patterns and processes of heterogeneous landscapes, and describes the general structure of a hierarchical urban landscape model (HPDM-PHX) which is developed using this modeling approach.

TL;DR: A spatial evaluation of climate impact on the Envelope of species (SPECIES) as discussed by the authors was developed to evaluate the impacts of climate change on the bioclimatic envelope of plant species in Great Britain.

TL;DR: In this paper, generalized regression analysis and spatial prediction (GRASP) is proposed as a method for producing spatial predictions using statistical models, and a specific implementation in Splus that facilitates the process.

TL;DR: Five modelling techniques were compared for mapping forest characteristics in the Interior Western United States and tremendous advantages were seen in use of MARS and ANN for prediction over LMs, GAMs, and CART.

TL;DR: The empirical models appeared more accurate in their predictions than mechanistic models, but they are highly dependent on the data used for parameterisation that makes them unsuitable for extrapolation to other systems or conditions.

TL;DR: In this article, Huisman-Olff-Fresco (HOF) models were used to evaluate the shape of vascular plant responses along an elevation gradient. But, the results showed that the skewed and plateau responses are less common than symmetric responses.

TL;DR: In this article, the authors describe a flexible method for modelling zero inflated count data, which are typically found when trying to model and predict species distributions, and extend previous work to incorporate the use of generalized additive models (GAM) in the modelling steps.

TL;DR: This paper reviews the aspects of uncertainty that are relevant to habitat maps developed with logistic regression, and suggests methods for investigating and communicating these uncertainties.

TL;DR: In this article, generalized linear models (GLMs) and classification trees were developed to predict the presence of four vegetation alliances in a section of the Mojave Desert in California, and the models were used to generate a map of predictions for each alliance.

TL;DR: In this article, the authors present a new model of the terrestrial carbon cycle (Sim-CYCLE), with the objectives of retrieving the carbon dynamics of various terrestrial ecosystems and estimating their response to global environmental change.

TL;DR: In this paper, a hybrid, monthly time-step model of forest growth and carbon dynamics (TRIPLEX) is described and tested, which is designed as a hybrid of both empirical and mechanistic components that can be used for making forest management decisions (e.g. growth and yield prediction), quantifying forest carbon budgets, and assessing the effects of climate change in both the short and long term.

TL;DR: Li et al. as discussed by the authors developed an agroecosystem model (Crop-DNDC) by integrating detailed crop growth algorithms with an existing soil biogeochemical model, DNDC.

TL;DR: In this article, the conditions under which landscape structure affects dispersal success and the dependency of success on the choice of dispersal algorithm were explored. But the authors did not consider the effect of landscape structure on dispersal performance.

TL;DR: In this paper, the authors present and relate four different frameworks in which spatially explicit individual-based models (IBMs) can be defined, which differ in the way space and time are modeled; each can be treated either discretely or continuously.

TL;DR: A water quality modeling study was performed for water quality management of large river systems where autochthonous sources and denitrification play an important role in biochemical oxygen demand (BOD) and nitrogen dynamics as mentioned in this paper.

TL;DR: In this article, the authors performed several simulation experiments using the spatially explicit, multiple pathway model a LANDscape Succession Model (LANDSUM) to quantify the range and variability in six class and landscape pattern metrics for four landscapes in the northwestern United States.

TL;DR: This article presents a cellular automaton (CA) model that is capable of predicting fire spread in spatially heterogeneous Savanna systems and was found to satisfactorily predict spatial fire behaviour.

TL;DR: In this article, the authors developed a general model of temperature sensitivity of soil respiration that explicitly considers this nonlinearity, and used it to assess the uncertainty in estimating the soil CO2 efflux with several commonly used ecosystem models.

TL;DR: In this paper, a model is developed to predict drought-induced mortality of woody plants under different climatic scenarios, assuming that plant mortality is controlled by the carbon balance: when the plant is unable to transport water to the leaves it ceases to acquire carbon and, if this situation lasts long enough, it can no longer survive.